decibels above reference noise
Also found in: Acronyms.
decibels above reference noise[′des·ə·bəlz ə¦bəv ′ref·rəns ‚nȯiz]
Units used to show the relationship between the interfering effect of a noise frequency, or band of noise frequencies, and a fixed amount of noise power commonly called reference noise; a 1000-hertz tone having a power level of -90 dBm was selected as the reference noise power; superseded by the adjusted decibel unit. Abbreviated dBrn.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.